Process for producing an imaging member belt having an angular seam

ABSTRACT

There is provided a process for producing a seamed, flexible electrostatographic imaging member belt comprising providing a flexible, substantially rectangular, electrostatographic imaging sheet having a first major exterior surface opposite and parallel to a second major exterior surface and a first marginal end region of said sheet opposite and parallel with a second marginal end region; shaping said first marginal end region at an angle to form a first new sloping surface between the first major exterior surface and the second major exterior surface, shaping said second marginal end region at an angle to form a second new sloping surface between the first major exterior surface and the second major exterior surface, wherein the second new sloping surface is substantially parallel with the first new sloping surface; forming the sheet into a loop and overlapping said first new sloping surface with said second new sloping surface to form a mated region; and, joining said first new sloping surface to said second new sloping surface in the mated region to form a thin profile butt-lap seam. The sloping surfaces may be formed using a cutting assembly in accordance with the disclosure.

CROSS REFERENCE TO RELATED APPLICATIONS

This application also relates to U.S. patent application Ser. No.11/193,913, filed concurrently herewith, the disclosure of which ishereby incorporated by reference in its entirety.

BACKGROUND

Disclosed herein is a process for producing an imaging member belthaving an angular seam design. This disclosure also provides a flexibleimaging member belt having a number of morphological improvements and,more specifically, to the creation of a thin and smooth profile seam forflexible electrostatographic imaging member belts.

Flexible electrostatographic belt imaging members are well known.Typical electrostatographic flexible belt imaging members include, forexample, photoreceptors for electrophotographic imaging systems,electroreceptors such as ionographic imaging members for electrographicimaging systems, and intermediate image transfer belts for transferringtoner images in electrophotographic and electrographic imaging systems.These belts are usually formed by cutting a rectangular, a square, or aparallelogram shape sheet from a web containing at least one layer ofthermoplastic polymeric material, overlapping opposite ends of thesheet, and joining the overlapped ends together to form a seam. The seamtypically extends from one edge of the belt to the opposite edge.

Generally, these belts comprise at least a supporting substrate layerand at least one imaging layer comprising thermoplastic polymeric matrixmaterial. The “imaging layer” as employed herein is defined as thedielectric imaging layer of an electroreceptor belt, the transfer layerof an intermediate transfer belt and, the charge transport layer of anelectrophotographic belt. Thus, the thermoplastic polymeric matrixmaterial in the imaging layer is located in the upper portion of a crosssection of an electrostatographic imaging member belt, the substratelayer being in the lower portion of the cross section of theelectrostatographic imaging member belt. Although the flexible belts ofinterest include the mentioned types, for simplicity reasons, thediscussion hereinafter will be focus on the electrophotographic imagingmember belts.

Flexible electrophotographic imaging member belts are usuallymultilayered photoreceptors that comprise a substrate, an electricallyconductive layer, an optional hole blocking layer, an adhesive layer, acharge generating layer, and a charge transport layer and, in someembodiments, an anti-curl backing layer. One type of multilayeredphotoreceptor comprises a layer of finely divided particles of aphotoconductive inorganic compound dispersed in an electricallyinsulating organic resin binder. A typical layered photoreceptor havingseparate charge generating (photogenerating) and charge transport layersis described in U.S. Pat. No. 4,265,990, the entire disclosure thereofbeing incorporated herein by reference. The charge generating layer iscapable of photogenerating holes and injecting the photogenerated holesinto the charge transport layer.

Although excellent toner images may be obtained with multilayered beltphotoreceptors, it has been found that as more advanced, higher speedelectrophotographic copiers, duplicators and printers have beendeveloped, fatigue induced cracking of the charge transport layer at thewelded seam area is frequently encountered during photoreceptor beltcycling. Moreover, the onset of seam cracking has also been found torapidly lead to seam delamination due to fatigue thereby shortening beltservice life.

The flexible electrostatographic imaging member belts are fabricatedfrom a sheet cut from an imaging member web. The sheets are generallyrectangular or parallelogram in shape. All edges may be of the samelength or one pair of parallel edges may be longer than the other pairof parallel edges. The sheets are formed into a belt by joiningoverlapping opposite marginal end regions of the sheet. A seam istypically produced in the overlapping marginal end regions at the pointof joining. Joining may be effected by any suitable means. Typicaljoining techniques include welding (including ultrasonic), gluing,taping, pressure heat fusing, and the like. Ultrasonic welding isgenerally the preferred method of joining because it is rapid, clean (nosolvents) and produces a thin and narrow seam. In addition, ultrasonicwelding is preferred because the mechanical pounding of the welding horncauses generation of heat at the contiguous overlapping end marginalregions of the sheet to maximize melting of one or more layers therein.A typical ultrasonic welding process is carried out by holding down theoverlapped ends of a flexible imaging member sheet with vacuum against aflat anvil surface and guiding the flat end of an ultrasonic vibratinghorn transversely across the width of the sheet, over and along thelength of the overlapped ends, to form a welded seam.

When ultrasonically welded into a belt, the seam of multilayeredelectrophotographic imaging flexible member belts may occasionallycontain undesirable high protrusions such as peaks, ridges, spikes, andmounds. These seam protrusions present problems during image cycling ofthe belt machine because they interact with cleaning blades to causeblade wear and tear which ultimately affect cleaning blade efficiencyand service life. Moreover, the protrusion high spots in the seam mayalso interfere with the operation of subsystems of copiers, printers andduplicators by damaging electrode wires used in development subsystemsthat position the wires parallel to and closely spaced from the outerimaging surface of belt photoreceptors. These closely spaced wires areemployed to facilitate the formation of a toner powder cloud at adevelopment zone adjacent to a toner donor roll and the imaging surfaceof the belt imaging member.

Another frequently observed mechanical failure in the imaging beltsduring image cycling is that the ultrasonically welded seam of anelectrophotographic imaging member belt can also cause initiation ofcracks in the seam which then propagate and lead to delamination afterbeing subjected to extended bending and flexing cycles over smalldiameter belt support rollers of an imaging machine or when due tolateral forces caused by mechanical rubbing contact against stationaryweb edge guides of a belt support module during cycling. Seam crackingand delamination has also been found to be further aggravated when thebelt is employed in electrophotographic imaging systems utilizing bladecleaning devices and some operational imaging subsystems. Alteration ofmaterials in the various photoreceptor belt layers such as theconductive layer, hole blocking layer, adhesive layer, charge generatinglayer, and/or charge transport layer to suppress cracking anddelamination problems is not easily accomplished. The alteration of thematerials may adversely impact the overall physical, electrical,mechanical, and other properties of the belt such as well as coatinglayer uniformity, residual voltage, background, dark decay, flexibility,and the like.

For example, when a flexible imaging member belt used in anelectrophotographic machine is a photoreceptor belt fabricated byultrasonic welding of overlapped opposite ends of a sheet, theultrasonic energy transmitted to the overlapped ends melts thethermoplastic sheet components in the overlap region to form a seam. Theultrasonic welded seam of a multilayered photoreceptor belt isrelatively brittle and low in strength and toughness. The joiningtechniques, particularly the welding process, can result in theformation of a splashing that projects out from either side of the seamin the overlap region of the belt. The overlap region and splashings oneach side of the overlap region comprise a strip from one edge of thebelt to the other that is referred herein as the “seam region”. The seamregion of a typical overlap seamed flexible belt is about 1.6 timesthicker than the thickness of the body of the belt. Because of thesplashing, a typical flexible imaging member seamed belt has sharp topsplashing height of about 76 micrometers above the surface of theimaging layer at the junction meeting point between the top splashingand the surface of the belt. The junction meeting point is theundesirable site of physical discontinuity which has been found to actas stress concentration point to facilitate early onset of seamcracking/delamination problems under dynamic fatigue imaging member beltmachine functioning conditions.

The photoreceptor belt in an electrophotographic imaging apparatusundergoes bending strain as the belt is cycled over a plurality ofsupport and drive rollers. The excessive thickness of the photoreceptorbelt in the seam region due to the presence of the splashing results ina large induced bending strain as the seam travels over each roller.Generally, small diameter support rollers are highly desirable forsimple, reliable copy paper stripping systems in electrophotographicimaging apparatus utilizing a photoreceptor belt system operating in avery confined space. Unfortunately, small diameter rollers, e.g., lessthan about 0.75 inch (19 millimeters) in diameter, raise the thresholdof mechanical performance criteria to such a high level thatphotoreceptor belt seam failure can become unacceptable for multilayeredbelt photoreceptors. For example, when bending over a 19 millimeterdiameter roller, a typical photoreceptor belt seam splashing may developa 0.96 percent tensile strain due to bending. This is 1.63 times greaterthan a 0.59 percent induced bending strain that develops within the restof the photoreceptor belt. Therefore, the 0.96 percent tensile strain inthe seam splashing region of the belt represents a 63 percent increasein stress placed upon the seam splashing region of the belt.

Under dynamic fatiguing conditions, the seam provides a focal point forstress concentration and becomes the point of crack initiation which isfurther developed into seam delamination causing premature mechanicalfailure in the belt. Thus, the splashing tends to shorten the mechanicallife of the seam and service life of the flexible member belts used incopiers, duplicators, and printers. Moreover, the known seam splashingsurface roughness has also been found to interfere with cleaning bladefunction resulting in premature blade wear problem causing its loss ofcleaning efficiency.

Although a solution to suppress the seam cracking/delamination problemshas been successfully demonstrated, as described in a prior art, by aspecific heat treatment process of a flexible electrophotographicimaging member belt with its seam parked directly on top of a 19 mmdiameter back support rod for stress-releasing treatment at atemperature slightly above the glass transition temperature (Tg) of thecharge transport layer of the imaging member, nevertheless this seamstress release process was also found to produce various undesirableeffects such as causing seam area imaging member set and development ofbelt ripples in the active electrophotographic imaging zones of the belt(e.g., the region beyond about 25.2 millimeters from either side fromthe midpoint of the seam). Moreover, the heat treatment can induceundesirable circumferential shrinkage of the imaging belt. The set inthe seam area of an imaging member mechanically adversely interacts withthe cleaning blade and impacts cleaning efficiency. The ripples in theimaging member belt manifest themselves as copy printout defects.Further, the heat induced imaging belt dimensional shrinkage alters theprecise dimensional specifications required for the belt. Another keyshortcoming associated with the prior art seam stress release heattreatment process is the extensive heat exposure of a large seam area.This extensive heat exposure heats both the seam area of the belt aswell as the rod supporting the seam. Since the belt must be cooled tobelow the glass transition temperature of the thermoplastic material inthe belt prior to removal from the support rod in order to produce thedesired degree of seam stress release in each belt, the heat treatmentand cooling cycle time is unduly long and leads to very high beltproduction costs. Furthermore, it has been found that seam cracking lifeextension can be achieved through seam stress processing, neverthelessthe surface roughness produced by seam splashing still producesdifficulties with respect to the cleaning blade function.

Since there is no effective way to prevent the generation of localizedhigh protrusion spots at the seam region, imaging member belts areinspected right after seam welding belt production process, manually byhand wearing a cotton glove through passing the index finger over theentire seam length. Belts found catching the glove by the protrusionspots are identified as production rejects. Both the time consumingprocedure of manual inspection and the number of seamed belts rejecteddue to the presence of high seam protrusion spots constitute asubstantial financial burden on the production cost of imaging memberbelts.

Therefore, there is a need to provide seamed flexible imaging belts withan improved seam morphology which can withstand greater dynamic fatigueconditions thereby extending belt service life. It is also important,from a production point of view, to reduce the unit manufacturing costof seamed imaging belts. This can be realized, in part, if a seam designcan be developed to provide a smooth surface free of protrusion spots,reduce seam thickness, with little or no splashing to eliminate orminimize physical discontinuity at the junction or mating point of theseam.

The following references may be relevant to certain aspects of thisdisclosure:

U.S. Pat. No. 5,688,355 to Yu, issued Nov. 18, 1997—A seamed flexiblebelt and process for fabricating the belt is disclosed. Multiple-layeredelectrophotographic imaging member belt is prepared by utilizing excimerlaser ablation technique to remove precision amount of material from thebottom and the top of two opposite ends of an imaging member cut sheetprior to overlapping the two opposite ends and ultrasonically weld theoverlap into a welded seam. The resulting multi-layered imaging memberbelt thus obtained has a welded seam of little added thickness andreduced amount of seam splashing formulation.

U.S. Pat. No. 5,698,358 to Yu, issued Dec. 16, 1997—Disclosed is aprocess including providing a flexible substantially rectangular sheethaving a first major exterior surface opposite and parallel to a secondmajor exterior surface, removing or displacing material from the firstexterior surface adjacent and parallel to a first edge of the sheet toform a new surface having an elongated, curvilinear “S” shaped profilewhen viewed in a direction parallel to the first edge, overlapping thenew first surface and a second surface adjacent a second edge of thesheet whereby the first new surface contacts the second surface to forma mated surface region, the second surface being adjacent to or part ofthe second major exterior surface to form a sheet into a loop, thesecond edge being at an end of the sheet opposite from the first edge,and permanently joining the new first surface to the second surface intoa seam to form a seamed belt. The resulting welded belt has a seamthickness of less than about 120 percent of the total thickness of thebelt.

U.S. Pat. No. 5,190,608 to Darcy et al., issued Mar. 2, 1993—A flexiblebelt is disclosed having an outwardly facing surface, a welded seamhaving irregular protrusion on the outwardly facing surface and a thinflexible strip laminated and covering the welded seam and protrusions.This belt may be fabricated by providing a flexible belt having anoutwardly facing surface and a welded seam having irregular protrusionson the outwardly facing surface and laminating a thin flexible strip tothe welded seam. The belt may be used in an electrostatographic imagingprocess.

U.S. Pat. No. 5,549,999 to Swain et al., issued Aug. 27, 1996—Disclosedis a process for coating flexible belt seams including providing aflexible belt having an outwardly facing surface and a welded seam,forming a smooth liquid coating comprising a hardenable film formingpolymer on the welded seam, the coating being substantially free offugitive solvent, and hardening the coating to form a smooth solidcoating on the seam.

U.S. Pat. No. 5,582,949 to Bigelow et al., issued Dec. 10, 1996—Aprocess for coating flexible belt seams is disclosed wherein the processincludes providing a flexible belt having an outwardly facing surfaceand a welded seam, forming a smooth liquid coating on the welded seam,the liquid coating comprising a film forming polymer and a fugitiveliquid carrier in which the belt surface is substantially insoluble, andremoving the fugitive liquid carrier to form a smooth solid coating onthe seam.

U.S. Pat. No. 6,328,922 B1 to Mishra et al., issued Dec. 11, 2001—Aprocess for the post treatment of an imaging member belt includingproviding a support member having a smooth flat surface, proving aflexible belt having a welded seam, supporting the inner surface of theseam on the smooth flat surface, contacting the seam with a heatedsurface, heating the seam region with the heated surface to raise thetemperature in the seam region to a temperature of from about 2° C. to20° C. about the Tg of the thermoplastic polymer material, andcompressing the seam with the heated surface with sufficient compressionpressure to smooth out the seam is disclosed herein.

U.S. Pat. No. 5,552,005 to Mammino et al., issued Sep. 3, 1996—Aflexible imaging sheet and a method of constructing a flexible imagingsheet is disclosed. The method of constructing a flexible imaging sheetcomprises the steps of overlapping, joining, and shaping. In the step ofoverlapping, a first marginal end region and a second marginal endregion of a sheet are overlapped to form an overlap region and anon-overlap region. In the step of joining, the first marginal endregion and the second marginal end region of the sheet are joined to oneanother by a seam in the overlap region. In the step of shaping, theoverlap region is shaped to form a generally planar surface co-planarwith a surface of the non-overlap region. The flexible imaging sheetcomprises a first marginal end region and a second marginal end region.The first marginal end region and the second marginal end region aresecured by a seam to one another in the overlap region. The firstmarginal end region and the second marginal end region are substantiallyco-planar to minimize stress on the flexible imaging sheet. Minimizationof stress concentration, resulting from dynamic bending of the flexibleimaging sheet during cycling over a roller within an electrophotographicimaging apparatus, is disclosed therein.

U.S. Pat. No. 6,074,504 to Yu et al., issued Jun. 13, 2000—a process isdisclosed for treating a seamed flexible electrostatographic imagingbelt including providing an imaging belt having two parallel edges, thebelt comprising at least one layer comprising a thermoplastic polymermatrix and a seam extending from one edge of the belt to the other, theseam having an imaginary centerline, providing an elongated supportmember having at arcuate supporting surface and mass, the arcuatesurface having at least a substantially semicircular cross sectionhaving a radius of curvature of between about 9.5 millimeters and about50 millimeters, supporting the seam on the arcuate surface with theregion of the belt adjacent each side of the seam conforming to thearcuate supporting surface of the support member, precisely traversingthe length of the seam from one edge of the belt to the other withthermal energy radiation having a narrow Gaussian wavelengthdistribution of between about 10.4 micrometers and about 11.2micrometers emitted from a carbon dioxide laser, the thermal energyradiation forming a spot straddling the seam during traverse, the spothaving a width of between about 3 millimeters and about 25 millimetersmeasured in a direction perpendicular to the imaginary centerline of theseam, and rapidly quenching the seam by thermal conduction of heat fromthe seam to the mass of the support member to a temperature below theglass transition temperature of the polymer matrix while the region ofthe belt adjacent each side of the seam conforms to the arcuatesupporting surface of the support member.

While various innovative approaches have provided improvements inflexible belt seam morphology, nevertheless, it has been found that thesolution of one problem may also create other undesirable issues. Forexample, overcoating the seam of a photoreceptor belt with metallic foilcould cause electrical seam arcing. Moreover, application of liquidovercoating layer over the seam also induces the crystallization ofcharge transport molecules in the vicinity adjacent to the seamovercoat. Additionally, it was also observed that application of theliquid overcoating layer usually produced poor adhesion bond strength tothe seam after solidification into a dried coat. Thus, there is acontinuing need for electrostatographic imaging belts having improvedwelded seam designs that are thin in seam profile, resistant to seamcracking/delamination, free of seam protrusions, have improved seamregion physical continuity, and are free of factors that damage imagingsubsystems.

BRIEF DESCRIPTION

The present disclosure provides, in various embodiments thereof, anelectrostatographic imaging member belt that has an improved morphologythat overcomes one or more of the above-noted deficiencies. A processand apparatus for providing such an imaging member is also disclosedherein.

The present disclosure also provides in various embodiments thereof, aprocess and assembly for providing morphologically improved seam for anelectrostatographic imaging member belt.

Further, the present disclosure provides, in various embodimentsthereof, an electrostatographic imaging member belt having an improvedwelded seam that exhibits greater resistance to the onset of dynamicfatigue induced seam cracking and/or delamination.

The development disclosed herein provides, in various embodimentsthereof, an electrostatographic imaging member belt having an improvedwelded seam that provides good circumferential dimension tolerance androbust mechanical seam function as well.

The disclosure also provides, in various embodiments thereof, anelectrostatographic imaging member belt having an ultrasonically weldedseam that reduces cleaning blade wear.

Additionally, the development disclosed herein provides, in variousembodiments thereof, a seamed electrostatographic imaging member belthaving an improved welded seam that is substantially free of seamprotrusions, has little or no splashing, and has a smooth surfacemorphological profile. A process for manufacturing such an imagingmember is further disclosed herein.

Furthermore, the present disclosure provides, in various embodimentsthereof, a method to fabricate an electrostatographic imaging memberbelt having an improved welded seam that has little or no seam regionphysical discontinuity.

The development also provides, in various embodiments thereof, a seamedelectrostatographic imaging member belt with a reduced seam areathickness to minimize the seam region induced bending stress when theelectrostatographic imaging member belt flexes over small diameter beltmodule support rollers.

The foregoing aspects and others may be accomplished in accordance withthis disclosure by providing, in various embodiments thereof, a processfor producing a seamed, flexible electrostatographic imaging member beltby providing a flexible, substantially rectangular, electrostatographicimaging sheet having a first major exterior surface opposite andparallel to a second major exterior surface and a first marginal endregion of said sheet opposite and parallel with a second marginal endregion; providing an apparatus for cutting the imaging sheet, theapparatus comprising a support member, a blade support member connectedto the support member, and a blade assembly connected to the bladesupport members, the blade assembly having a cutting blade; shaping saidfirst marginal end region at an angle to form a first new slopingsurface between the first major exterior surface and the second majorexterior surface; shaping said second marginal end region at an angle toform a second new sloping surface between the first major exteriorsurface and the second major exterior surface, wherein the second newsloping surface is substantially parallel with the first new slopingsurface; forming the sheet into a loop and overlapping said first newsloping surface with said second new sloping surface to form a matedregion; and, joining said first new sloping surface to said second newsloping surface in the mated region to form a seam. Although the bondingof the mated sloping surfaces of the imaging member end pair into aseamed belt can be accomplished by gluing, stapling, solvent welding,ultrasonic welding process, and the like, nonetheless ultrasonic seamwelding is the process of particular preference based on the ease ofoperation, seam bonding strength, and economic considerations. Alsodisclosed herein is the seamed, flexible electrostatographic imagingmember belt produced by this process.

The disclosure also provides, in various embodiments thereof, a processfor producing a seamed, flexible electrostatographic imaging member beltcomprising a) providing a flexible, substantially rectangular,electrostatographic imaging sheet having a first major exterior surfaceopposite and parallel to a second major exterior surface and a firstmarginal end region of said sheet opposite and parallel with a secondmarginal end region; b) providing an apparatus for cutting the imagingsheet, the apparatus comprising i) a support member, ii) a blade supportmember connected to the support member, and iii) a blade assemblyconnected to the blade support member, the blade assembly having acutting blade; c) shaping said first marginal end region at an angle toform a first new sloping surface between the first major exteriorsurface and the second major exterior surface; d) shaping said secondmarginal end region at an angle to form a second new sloping surfacebetween the first major exterior surface and the second major exteriorsurface, wherein the second new sloping surface is substantiallyparallel with the first new sloping surface; e) forming the sheet into aloop and overlapping said first new sloping surface with said second newsloping surface to form a mated region; and f) joining said first newsloping surface to said second new sloping surface in the mated regionto form a seam, wherein the first and second sloping surfaces have anangle substantially equal to each other, the angle of the first andsecond sloping surfaces being less than 90°.

Further, the disclosure provides, in various embodiments thereof, Amethod for producing a seamed, flexible electrostatographic imagingmember belt comprising providing a flexible, substantially rectangular,electrostatographic imaging sheet having a top surface, a bottomsurface, a first major exterior surface opposite and parallel to asecond major exterior surface and a first marginal end region of saidsheet opposite and parallel with a second marginal end region; providinga cutting apparatus comprising i) a support member having an uppersurface, a lower surface, a first vertical surface, a second verticalsurface, a proximate end, and a distal end, ii) a blade support memberpivotably connected to the support member, the blade support membercomprising a pivot arm having a proximate end, a distal end, an upperportion adjacent the proximal end, and a lower portion adjacent theproximate end of the blade support member; and iii) a blade mountassembly connected to the blade support member, the blade mount assemblycomprising a cutting blade having a blade edge wherein the cutting bladeis oriented at an angle of about 45° or less relative to the top andbottom surfaces of the imaging sheet; shaping said first marginal endregion at an angle to form a first new angled surface between the firstmajor exterior surface and the second major exterior surface; shapingsaid second marginal end region at an angle to form a second new angledsurface between the first major exterior surface and the second majorexterior surface, wherein the second new angled surface is substantiallyparallel with the first new angled surface; forming the sheet into aloop and overlapping said first new angled surface with said second newangled surface to form a mated region; and joining said first new angledsurface to said second new angled surface in the mated region to form aseam.

Another embodiment disclosed herein is a flexible imaging member belthaving an angled, or angular, cross-sectional seam. The flexible imagingmember belt is produced by bisecting both ends of a flexible,substantially rectangular imaging member sheet at an angle relative tothe first and second major exterior surfaces of the sheet. The sheet islooped and the angled ends are then overlapped, mated, and joined orfused together to form a flexible imaging member belt. The angledcross-sectional seam so produced exhibits ample strength in comparisonto conventional overlapped seams with several morphologicalimprovements.

In a further embodiment, an ultrasonically welded, butt-lap seamedflexible imaging member belt is generated by producing a substantiallyrectangular flexible imaging sheet having two opposite ends, bisectingthe opposite ends of the sheet at a cross-sectional angle relative tothe sheet's first and second major exterior surfaces to generate a pairof matching, or complementary, slant-cut angles, forming a loop with thesheet and bringing the opposite ends together for mating, andultrasonically welding the mated opposite ends together to form a thinand smooth profile welded seam having an angled butt-lap seammorphology.

The resulting flexible imaging member belt has a smooth surface profile,little or no seam protrusion spots, a significant reduction in seamregion thickness, and provides seam region physical continuity as well.

Electrostatographic flexible belt imaging member may be prepared byvarious techniques. A typical flexible supporting substrate is providedwith an electrically conductive surface. For electrophotographic imagingmembers, at least one photoconductive layer is then applied to theelectrically conductive surface. A hole or electron blocking layer maybe applied to the electrically conductive surface prior to theapplication of the photoconductive layer. If desired, an adhesive layermay be utilized between the hole or electron blocking layer and thephotoconductive layer. For multilayered photoreceptors, a chargegeneration layer is usually applied onto the hole or electron blockinglayer and a charge transport layer is subsequently coated over thecharge generation layer. For ionographic imaging members, anelectrically insulating dielectric layer is applied directly onto theelectrically conductive surface.

The supporting substrate may be opaque or substantially transparent andmay comprise numerous materials having the required mechanicalproperties. Accordingly, the substrate may comprise a layer of anelectrically non-conductive or conductive material such as an inorganicor an organic composition. As electrically non-conducting materialsthere may be employed various thermoplastic resins known for thispurpose including polyesters, polycarbonates, polyamides, polyurethanes,and the like which are flexible in thin webs. The electricallyinsulating or conductive substrate should be flexible and in the form ofan endless flexible belt. Preferably, the endless flexible belt shapedsubstrate comprises a commercially available biaxially orientedpolyester.

The thickness of the supporting substrate layer depends on numerousfactors, including seam strength, mechanical toughness, and economicalconsiderations. Thus, the substrate layer used for a flexible beltapplication may be of substantial thickness, for example, about 150micrometers, or of a minimum thickness of about 50 micrometers, providedthat it produces no adverse effects on the belt. Preferably, thethickness of the substrate layer is between about 75 micrometers andabout 100 micrometers for optimum flexibility, beam rigidity, andminimum stretch during cycling.

Where a separate flexible conductive layer is employed, it may vary inthickness over substantially wide ranges depending on the opticaltransparency and degree of flexibility desired for theelectrostatographic member. Accordingly, for a flexibleelectrophotographic imaging device, the thickness of the conductivelayer may be between about 20 angstroms and about 750 angstroms, andmore preferably between about 100 angstroms and about 200 angstroms foran optimum combination of electrical conductivity, flexibility and lighttransmission. The flexible conductive layer may be an electricallyconductive metal layer formed, for example, on the substrate by anysuitable coating technique, such as a vacuum depositing technique.Typical metals include aluminum, copper, gold, zirconium, niobium,tantalum, vanadium and hafnium, titanium, nickel, stainless steel,chromium, tungsten, molybdenum, and the like. Regardless of thetechnique employed to form the metal layer, a thin layer of metal oxideforms on the outer surface of most metals upon exposure to air. Thus,when other layers overlying the metal layer are characterized as“contiguous” layers, it is intended that these overlying contiguouslayers may, in fact, contain a thin metal oxide layer that has formed onthe outer surface of an oxidizable metal layer. A typical electricalconductivity for conductive layers for electrophotographic imagingmembers in slow speed copiers is about 10-2 to 10-3 per ohms/square.

After formation of an electrically conductive surface, a hole blockingor electron blocking layer, hereinafter referred to as a charge blockinglayer, may be applied thereto for photoreceptors. Generally, electronblocking layers for positively charged photoreceptors allow holes fromthe imaging surface of the photoreceptor to migrate toward theconductive layer and hole blocking layers for negatively chargedphotoreceptors allow electrons from the imaging surface of thephotoreceptor to migrate toward the conductive layer. Any suitablecharge blocking layer capable of forming an electronic barrier to holesor electrons between the adjacent photoconductive layer and theunderlying conductive layer may be utilized. The charge blocking layermay be applied by any suitable conventional technique such as spraying,dip coating, draw bar coating, gravure coating, silk screening, airknife coating, reverse roll coating, vacuum deposition, chemicaltreatment and the like. The charge blocking layer should be continuousand have a dry thickness of less than about 0.2 micrometer.

An adhesive layer is usually applied to the charge blocking layer. Anysuitable adhesive layer well known in the art may be utilized. Typicaladhesive layer materials include, for example, polyesters,polyurethanes, and the like. Satisfactory results may be achieved withthe adhesive layer thickness between about 0.05 micrometer and about 0.3micrometer. Conventional techniques for applying an adhesive layercoating mixture to the charge blocking layer include spraying, dipcoating, roll coating, wire wound rod coating, gravure coating, Birdapplicator coating, and the like. Drying of the deposited coating may beeffected by any suitable conventional technique such as oven drying,infra red radiation drying, air drying and the like.

Any suitable charge generating (photogenerating) layer may be appliedonto the adhesive layer. Charge generating layers are well know in theart and can comprise homogeneous layers or photoconductive particlesdispersed in a film forming binder. Examples of charge generating layersare described, for example, in U.S. Pat. No. 3,357,989, U.S. Pat. No.3,442,781, and U.S. Pat. No. 4,415,639, the disclosures thereof beingincorporated herein in their entirety. Other suitable photogeneratingmaterials known in the art may also be utilized, if desired.

Any suitable polymeric film forming binder material may be employed asthe matrix in of the photogenerating layer. Typical polymeric filmforming materials include those described, for example, in U.S. Pat. No.3,121,006, the disclosure thereof being incorporated herein in itsentirety. The photogenerating composition or pigment may be present inthe film forming binder composition in various amounts. Generally, fromabout 5 percent by volume to about 90 percent by volume of thephotogenerating pigment is dispersed in about 10 percent by volume toabout 90 percent by volume of the resinous binder. Preferably from about20 percent by volume to about 30 percent by volume of thephotogenerating pigment is dispersed in about 70 percent by volume toabout 80 percent by volume of the resinous binder composition.

The photogenerating layer generally ranges in thickness from about 0.1micrometer to about 5 micrometers, and more preferably from about 0.3micrometer to about 3 micrometers. The photogenerating layer thicknessis related to binder content. Higher binder content compositionsgenerally require thicker layers for photogeneration.

Any suitable and conventional technique may be utilized to mix andthereafter apply the photogenerating layer coating mixture to thepreviously dried adhesive layer. Drying of the deposited coating may beeffected by any suitable conventional technique.

The charge transport layer may comprise any suitable transparent organicpolymer or non-polymeric material capable of supporting the injection ofphotogenerated holes or electrons from the charge generating layer andallowing the transport of these holes or electrons through the organiclayer to selectively discharge the surface charge. The charge transportlayer not only serves to transport holes or electrons, but also protectsthe photoconductive layer from abrasion or chemical attack. The chargetransport layer should exhibit negligible, if any, discharge whenexposed to a wavelength of light useful in xerography, e.g. 4000Angstroms to 9000 Angstroms. The charge transport layer is normallytransparent in a wavelength region in which the electrophotographicimaging member is to be used when exposure is effected therethrough toensure that most of the incident radiation is utilized by the underlyingcharge generating layer. When used with a transparent substrate,imagewise exposure or erase may be accomplished through the substratewith all light passing through the substrate. In this case, the chargetransport material need not transmit light in the wavelength region ofuse if the charge generating layer is sandwiched between the substrateand the charge transport layer. The charge transport layer inconjunction with the charge generating layer is an insulator to theextent that an electrostatic charge placed on the charge transport layeris not conducted in the absence of illumination. Charge transport layermaterials are well known in the art.

The charge transport layer may comprise activating compounds or chargetransport molecules dispersed in normally electrically inactive filmforming polymeric materials. These charge transport molecules may beadded to polymeric materials which are incapable of supporting theinjection of photogenerated holes and incapable of allowing thetransport of these holes. An especially preferred charge transport layeremployed in multilayer photoconductors comprises from about 25 percentto about 75 percent by weight of at least one charge transportingaromatic amine, and about 75 percent to about 25 percent by weight of apolymeric film forming resin in which the aromatic amine is soluble.Examples of typical charge transporting aromatic amines includetriphenylmethane, bis(4-diethylamine-2-methylphenyl)phenylmethane;4′-4″-bis(diethylamino)-2′,2″-dimethyltriphenylmethane;N,N′-bis(alkylphenyl)-(1,1′-biphenyl)-4,4′-diamine wherein the alkyl is,for example, methyl, ethyl, propyl, n-butyl, etc.;N,N′-diphenyl-N,N′-bis(3″-methylphenyl)-(1,1′ biphenyl)-4,4′ diamine;and the like, dispersed in an inactive resin binder.

Any suitable inactive thermoplastic resin binder may be employed.Typical inactive resin binders include polycarbonate resins,polyvinylcarbazole, polyester, polyarylate, polyacrylate, polyether,polysulfone, and the like. Molecular weights can vary from about 20,000to about 150,000.

The thickness of the charge transport layer may range from about 10micrometers to about 50 micrometers, and preferably from about 20micrometers to about 35 micrometers. Optimum thicknesses may range fromabout 23 micrometers to about 31 micrometers.

An optional conventional ground strip may be utilized along one edge ofthe electrophotographic imaging member. The ground strip may comprise afilm forming polymer binder and electrically conductive particles. Theground strip may comprise materials such as those enumerated in U.S.Pat. No. 4,664,995. The ground strip layer may have a thickness fromabout 7 micrometers to about 42 micrometers, and preferably from about14 micrometers to about 23 micrometers.

An optional conventional anti-curl layer may also be employed. Theanti-curl layer may comprise thermoplastic organic polymers or inorganicpolymers that are electrically insulating or slightly semi-conductive.The anti-curl layer provides flatness and/or abrasion resistance and mayalso contain microcrystalline silica or organic particulates to improveits frictional and wear properties. The anti-curl layer is formed at theback side of the substrate, opposite to the imaging layers. Thethickness of the anti-curl layer is from about 3 micrometers to about 35micrometers. An example of an anti-curl backing layer is described inU.S. Pat. No. 4,654,284, the entire disclosure of this patent beingincorporated herein by reference.

An optional conventional overcoating layer may also be used. Theoptional overcoating layer may comprise organic polymers or inorganicpolymers that are electrically insulating or slightly semi-conductive.The overcoating layer may range in thickness from about 2 micrometers toabout 8 micrometers, and preferably from about 3 micrometers to about 6micrometers.

For electrographic imaging members, a flexible dielectric layeroverlying the conductive layer may be substituted for thephotoconductive layers. Any suitable, conventional, flexible,electrically insulating dielectric thermoplastic polymer may be used inthe dielectric layer of the electrographic imaging member. If desired,the concept of the morphologically improved seam configuration of thisdisclosure may be extended to flexible belts having different materialcompositions where cycling durability is important.

The above processes, compositions and materials can be utilized toproduce a seamed flexible imaging member belt having a sufficientstrength, smooth surface profile with little or no seam protrusion spotsand little, if any, increase in seam thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the processes and apparatuses disclosedherein can be obtained by reference to the accompanying drawings. Thesefigures are merely schematic representations based on convenience andthe ease of demonstrating the existing art and the present development,and are, therefore, not intended to indicate relative size anddimensions of the flexible imaging member belts or components thereofand/or to define or limit the scope of the exemplary embodiments.

FIG. 1 illustrates a schematic partial cross-sectional view of a known,looped multiple layered flexible sheet of electrophotographic imagingmember material having vertically cut opposite ends in an overlappedposition;

FIG. 2 shows a schematic partial cross-sectional view of a typicalmultiple layered seamed flexible electrophotographic imaging member beltderived from the sheet illustrated in FIG. 1 after ultrasonic seamwelding;

FIG. 3 illustrates a schematic partial cross-sectional view of amultiple layered seamed flexible electrophotographic imaging member beltof FIG. 2 which has mechanical failure due to fatigue induced seam areacracking/delamination;

FIG. 4 shows the cross sectional side view of a seamed, flexiblemultiple layered electrophotographic imaging member belt of the presentdisclosure;

FIG. 5 illustrates the surface profile of a control seam;

FIG. 6 shows the surface profile of a seam design disclosed herein;

FIG. 7 depicts a perspective view of a cutting assembly for providing anangled or beveled surface in an imaging member sheet;

FIG. 8 is an exploded view of the cutting assembly of FIG. 7;

FIG. 9 is a front elevational view of the cutting assembly of FIG. 7;

FIG. 10 is a side elevational view of the right side of the cuttingassembly of FIG. 7;

FIG. 11 is a side elevational view of the left side of the cuttingassembly of FIG. 7;

FIG. 12 is a detail of an embodiment of an embodiment of a cutting bladesuitable for use with a cutting assembly in accordance with thedisclosure;

FIG. 13 is a schematic representation of an apparatus or system forforming an angled or beveled surface in an imaging member sheetemploying the cutting assembly of FIG. 7; and

FIG. 14 is a detail of the left hand portion of the system of FIG. 13.

Still further advantages and benefits of the present exemplaryembodiments will become apparent to those of ordinary skill in the artupon reading and understanding the following detailed description of thepreferred embodiments.

DETAILED DESCRIPTION

Although specific terms are used in the following description for thesake of clarity, these terms are intended to refer only to theparticular structure of the embodiments selected for illustration in thedrawings, and are not intended to define or limit the scope of thedisclosure. In the drawings and the following description below, it isto be understood that like numeric designations refer to components oflike function.

Referring to FIG. 1, there is illustrated a flexible electrophotographicimaging member 10 in the form of a looped sheet having a first endmarginal region 12 overlapping a second end marginal region 14 to forman overlap region ready for a known seam forming operation. The flexibleelectrophotographic member 10 can be utilized within anelectrophotographic imaging device and may be a single film substratemember or a member having a film substrate layer combined with one ormore additional coating layers. At least one of the coating layerscomprises a film forming binder.

The flexible electrophotographic imaging member 10 may be a single layeror a multiple layer type photoreceptor. If the flexibleelectrophotographic imaging member 10 is to be a negatively chargedphotoreceptor device, the flexible electrophotographic imaging member 10may comprise a charge generator layer sandwiched between a conductivesurface and a charge transport layer. Alternatively, if the flexibleimaging member 10 is to be a positively charged photoreceptor device,the flexible imaging member 10 may comprise a charge transport layersandwiched between a conductive surface and a charge generator layer.

The layers of the flexible electrophotographic imaging member 10 cancomprise numerous suitable materials having suitable mechanicalproperties. Examples of typical layers are described in U.S. Pat. No.4,786,570; U.S. Pat. No. 4,937,117; and, U.S. Pat. No. 5,021,309, theentire disclosures thereof being incorporated herein by reference. Thebelt of flexible electrophotographic imaging member 10 shown in FIG. 1,including the two end marginal regions 12 and 14, comprises from top tobottom a charge transport layer 16, a generator layer 18, an interfacelayer 20, a blocking layer 22, a conductive ground plane layer 24, asupporting layer 26, and an anti-curl back coating layer 28. It shouldbe understood that the thicknesses of the layers in the embodiment ofFIG. 1 are conventional and that a wide range of thicknesses can be usedfor each of the layers.

The end marginal regions 12 and 14 can be joined by any suitable meansincluding gluing, taping, stapling, pressure and heat fusing to form acontinuous member such as a belt, sleeve, or cylinder, nevertheless,from the viewpoint of considerations such as ease of belt fabrication,short operation cycle time, and the mechanical strength of thefabricated joint, the ultrasonic welding process is preferably used tojoin the end marginal regions 12 and 14 of flexible electrophotographicimaging member sheet 10 into a seam 30 in the overlap region, as shownin FIG. 2, to form a seamed flexible electrophotographic imaging memberbelt 10.

As illustrated in FIG. 2, the location of seam 30 is indicated by adotted line. Seam 30 comprises two vertical portions joined by ahorizontal portion. Thus, the midpoint of seam 30 may be represented byan imaginary centerline extending the length of seam 30 from one edge ofbelt 10 to the opposite edge, the imaginary centerline (not shown)running along the middle of the horizontal portion which joins the twovertical portions illustrated in FIG. 2. In other words, a plain view(not shown) of the horizontal portion of seam 30 would show a strip muchlike a two lane highway in which the centerline would be represented bythe white divider line separating the two lanes, the two lanescomprising end marginal regions 12 and 14. The flexibleelectrophotographic imaging member 10 is thus transformed from a sheetof electrophotographic imaging member material as illustrated in FIG. 1into a continuous electrophotographic imaging member belt as illustratedin FIG. 2.

The flexible electrophotographic imaging member 10 has a first major orupper exterior surface or side 32 and a second major or lower exteriorsurface or side 34 on the opposite side. The seam 30 joins the flexibleelectrophotographic imaging member 10 so that the lower surface 34(generally including at least one layer immediately above) at and/ornear the first end marginal region 12 is integral with the upper surface32 (generally including at east one layer immediately below) at and/ornear the second end marginal region 14.

A preferred heat/pressure joining means includes ultrasonic welding totransform the sheet of photoconductive imaging material into aphotoreceptor belt. The belt can be fabricated by ultrasonic welding ofthe overlapped opposite end regions of a sheet. In the ultrasonic seamwelding process, ultrasonic energy applied to the overlap region is usedto melt suitable layers such as the charge transport layer 16, generatorlayer 18, interface layer 20, blocking layer 22, part of the supportlayer 26 and/or anti-curl back coating layer 28. Direct fusing of thesupport layer achieves optimum seam strength.

Upon completion of welding the overlap region of the flexibleelectrophotographic imaging member sheet into a seam 30 using ultrasonicseam welding technique, the overlap region is transformed into anoverlapping and abutting region as illustrated in FIGS. 2 and 3. Withinthe overlapping and abutting region, the portions of the flexibleelectrophotographic imaging member 10, which once formed the endmarginal regions 12 and 14, are joined by the seam 30 such that the onceend marginal regions 12 and 14 are overlapping and abutting one another.The welded seam 30 contains upper and lower splashings 68 and 70 at eachend thereof as illustrated in FIGS. 2 and 3.

The splashings 68 and 70 are formed in the process of joining the endmarginal regions 12 and 14 together. Molten material is necessarilyejected from either side of the overlap region to facilitate directsupport layer 26 to support layer fusing and results in the formation ofthe splashings 68 and 70. The upper splashing 68 is formed andpositioned above the overlapping end marginal region 14 abutting the topsurface 32 and adjacent to and abutting the overlapping end marginalregion 12. The lower splashing 70 is formed and positioned below theoverlapping end marginal region 12 abutting bottom surface 34 andadjacent to and abutting the overlapping end marginal region 14. Thesplashings 68 and 70 extend beyond the sides and the edges of the seam30 in the overlap region of the welded flexible electrophotographicimaging member 10. The extension of the splashings 68 and 70 beyond thesides and the edges of the seam 30 is undesirable for many machines suchas electrophotographic copiers, duplicators and copiers that requireprecise edge positioning of a flexible electrophotographic imagingmember 10 during machine operation. Generally, the extension of thesplashings 68 and 70 at the belt edges of the flexibleelectrophotographic imaging member 10 are removed by a notchingoperation.

A typical upper splashing 68 has a height or thickness t of about 90micrometers and projects about 17 microns above the surface of theoverlapping end marginal region 12. Each of the splashings 68 and 70 hasan uneven but generally rectangular shape including one side (free side)72 (which forms a free end) extending inwardly toward top surface 32from an outwardly facing side 74 (extending generally parallel to eitherthe top surface 32 or the bottom surface 34). The free side 72 of thesplashing 68 forms an approximately perpendicular angle θ₁ with thebottom surface 34 of the flexible electrophotographic imaging member 10.Likewise, the free side 72 of the splashing 70 forms an approximatelyperpendicular angle θ₂ at the junction 78 of the free side 72 of thelower splashing 70 and the bottom surface 34 of the flexible imagingmember belt 10. Likewise, a meeting or junction point 78 exists at thejunction of the free side 72 of the lower splashing 70 and the bottomsurface 34 of the flexible electrophotographic imaging member belt 10.Both junction points 76 and 78 provide focal points for the stressconcentration and become the initial points of failure affecting themechanical integrity of the flexible electrophotographic imaging memberbelt 10.

During machine operation, the seamed flexible electrophotographicimaging member belt 10 cycles or bends over rollers, particularly smalldiameter rollers, of a belt support module within an electrophotographicimaging apparatus. As a result of dynamic bending/flexing of theflexible electrophotographic imaging member belt 10 during cycling, therollers repeatedly exert a force on the flexible imaging member belt 10which causes large stresses to develop generally adjacent to the seam 30due to the excessive thickness and material discontinuity thereof. Thestress concentrations that are induced by bending near the junctionpoints 76 and 78 may reach values much larger than the average value ofthe stress over the entire length of the flexible electrophotographicimaging member belt 10. The induced bending stress is inversely relatedto the diameters of a roller that the flexible imaging member 10 bendsover and directly related to the thickness of the seam region of theflexible electrophotographic imaging member belt 10. When a structuralmember, such as the flexible electrophotographic imaging member belt 10,contains a sudden increase in cross-sectional thickness at the overlapregion, high localized stress occurs near the discontinuity, e.g.,junction points 76 and 78.

When the flexible electrophotographic imaging member belt 10 bends overthe rollers of a belt module within an electrophotographic imagingapparatus, the bottom surface 34 of the flexible electrophotographicimaging member belt 10, which is adapted to contact the exterior surfaceof the roller, is compressed. In contrast, the top surface 32 isstretched under tension. This is attributable to the fact that the topsurface 32 and bottom surface 34 move in a circular path about thecircular roller. Since the top surface 32 is at greater radial distancefrom the center of the circular roller than the bottom surface 34, thetop surface 32 must travel a greater distance than the bottom surface 34in the same time period. Therefore, the top surface 32 must be stretchedunder tension relative to a generally central portion of the flexibleelectrophotographic imaging member belt 10 (the portion of the flexibleelectrophotographic imaging member belt 10 generally extending along thecenter of gravity of the flexible imaging member 10). Likewise, thebottom surface 34 must be compressed relative to the generally centralportion of the flexible imaging member 10 (the portion of the flexibleelectrophotographic imaging member belt 10 generally extending along thecenter of gravity of the flexible electrophotographic imaging memberbelt 10). Consequently, the bending stress at the junction point 76 willbe tension stress, and the bending stress at the junction point 78 willbe compression stress.

Compression stresses, such as at the junction point 78, rarely causeseam 30 failure. Tension stresses, such as at junction point 76,however, are much more of a problem. The tension stress concentration atthe junction point 76 in great likelihood will eventually result incrack initiation through the electrically active layers of the flexibleelectrophotographic imaging member belt 10 as illustrated in FIG. 3. Theillustrated crack 80 is adjacent to the top splashing 68 of the secondend marginal region 14 of the flexible electrophotographic imagingmember belt 10. The generally vertically extending crack 80 initiated inthe charge transport layer 16 continues to propagate through thegenerator layer 18. Inevitably, the crack 80 extends generallyhorizontally to develop seam delamination 81 which is propagated throughthe relatively weak adhesion bond between the adjoining surfaces of thegenerator layer 18 and the interface layer 20.

The formation of the local seam delamination 81 is typically referred toas seam puffing. The excess thickness of the splashing 68 and stressconcentration at the junction 76 causes the flexible electrophotographicimaging member belt 10 to perform, during extended machine operation, asif a material defect existed therein. Thus, the splashing 68 tends topromote the development of dynamic fatigue seam 30 failure and can leadto separation of the joined end marginal regions 12 and 14 severing theflexible imaging member 10. Consequently, the service life of theflexible imaging member 10 is shortened.

In addition to seam failure, the crack 80 acts as a depository site andcollects toner, paper fibers, dirt, debris and other unwanted materialsduring electrophotographic imaging and cleaning of the flexibleelectrophotographic imaging member belt 10. For example, during thecleaning process, a cleaning instrument, such as a cleaning blade, willrepeatedly pass over the crack 80. As the site of the crack 80 becomesfilled with debris, the cleaning instrument dislodges at least someportion of this highly concentrated level of debris from the crack 80.The amount of the debris, however, is beyond the removal capacity of thecleaning instrument. As a consequence, the cleaning instrument dislodgesthe highly concentrated level of debris but cannot remove the entireamount during the cleaning process. Instead, portions of the highlyconcentrated debris are deposited onto the surface of the flexibleelectrophotographic imaging member belt 10. In effect, the cleaninginstrument spreads the debris across the surface of the flexibleelectrophotographic imaging member belt 10 instead of removing thedebris therefrom.

In addition to seam failure and debris spreading, the portion of theflexible member 10 above the seam delamination 81, in effect, becomes aflap which moves upwardly. The upward movement of the flap presents anadditional problem during the cleaning operation. The flap becomes anobstacle in the path of the cleaning instrument as the instrumenttravels across the surface of the flexible electrophotographic imagingmember belt 10. The cleaning instrument eventually strikes the flap whenthe flap extends upwardly. As the cleaning instrument strikes the flap,great force is exerted on the cleaning instrument which can lead todamage thereof, e.g., excessive wear and tearing of the cleaning blade.

In addition to damaging the cleaning blade, the striking of the flap bythe cleaning instrument causes unwanted vibration in the flexibleelectrophotographic imaging member belt 10. This unwanted vibrationadversely affects the copy/print quality produced by the flexibleelectrophotographic imaging member belt 10. The copy/print is affectedbecause imaging occurs on one part of the flexible imaging member 10simultaneously with the cleaning of another part of the flexible imagingmember 10.

In FIG. 4, the cross-sectional side view is shown of an embodimentdirected to an enhanced seam design formed by an ultrasonic weldingprocess. In this view, a flexible electrophotographic imaging belt 10 isshown after material has been removed or displaced from both ends of aflexible, substantially rectangular sheet on an angle A° to form two newangled or sloped, substantially parallel, cross-sectional ends, 13 and15. The sheet is then formed into a loop, the two new matching orcomplementary angled (or sloped) cross-sectional ends 13 and 15 areoverlayed upon one another and/or mated, and subsequently joinedtogether or fused, such as by an ultrasonic welding process, to form aseam 30A.

More particularly, illustrated in FIG. 4 is a schematic depiction offlexible imaging member 10 having a supporting substrate 26 sandwichedbetween an anti-curl backing layer 28 and composite layer 84 whichschematically depicts (for purposes of illustration simplification) acombination of charge transport layer 16, charge generating layer 18,adhesive layer 20, charge blocking layer 22, and conductive layer 24. InFIG. 4, flexible imaging member 10 is shown after material has beenremoved from first major or lower exterior surface 34 adjacent andparallel to first edge 12 of flexible imaging member 10 at an angle A°to form a new first angled or sloped surface 13. Also shown is flexibleimaging member 10 after material has been removed from second major orupper exterior surface 32 adjacent and parallel to second edge 14 toform a new second angled or sloped surface 15 which substantiallycomplements the profile of the first new angled or sloped surface 13.

After first new angled or sloped surface 13 and second new angled orsloped surface 15 are brought into contact with each other to form amated surface region and ultrasonically welded together, they form anexcellent overlapped joint having a thickness substantially similar tothe thickness of flexible imaging member 10 in regions that are notoverlapped. This configuration of overlapped opposite edges of a sheetallows direct contact of the support substrate at both ends of theoriginal sheet regions for intimate fusion to each other during anultrasonic seam welding process. As a result, little or no moltenmixtures of imaging layer material are ejected out to either side of theseam overlap. Direct fusing of supporting substrate 26 at new firstsurface 13 to supporting substrate 26 at new second surface 15 providesample seam strength, because of the enlarged area of exposed supportingsubstrate 26 material that are mated, as well as enhanced supportsubstrate contact for improved ultrasonic fusing.

In the embodiment shown in FIG. 4, seam 30A is the result of the joiningof two overlayed, cross-sectional angular ends. In this regard, seam 30Ais angled with respect to the upper and lower major surfaces of theabutted ends of the first end marginal region 12 and second end marginalregion 14 to form a flexible electrophotographic imaging belt 10. Seam30A is formed by an angular cut or slice through the cross-sectionalthickness of belt 10 at end marginal regions 12 and 14 at a slantingangle A°. In comparison to the overlapping seam 30 counterpart of FIG.2, seam 30A is a butt-lap hybrid joint that minimizes the physicaldiscontinuity. Furthermore, the seam region created has a smoothersurface with little or no added thickness and it is substantially freeof upper and lower seam splashing.

To prepare the seam design of FIG. 4, the angled, opposite ends of themarginal regions 12 and 14 are created by specific tilted or slantedcross-sectional cutting techniques to produce a pair of substantiallyparallel, angular or beveled matching ends. When the sheet is looped,the angular or beveled ends are overlayed over one another, mated andjoined or fused by, for example, sonic welding, to form a seam having aslant angle A°. The slant angle A° should be from about 5° to about 45°to effect proper mating and yield satisfactory seam welding operation.However, as a result of the difficulties in tilted or slantedcross-sectional cutting through the thickness of the belt 10 to createthe pair of beveled or angled ends and optimum ultrasonic seam weldingtechniques, the slant angle A is, in embodiments, from about 5° to about20° to yield enhanced seam rupture strength. Furthermore, it has beenfound that a slanted 19° cut angle, 40 kHz welded seam produces a smoothseam region topology, with reduced amount of seam splashings and verylittle added thickness. In this regard, it has been found that thehighest differential in thickness between the angled butt-lap seam andthe rest of the belt (the non-seamed portions of the belt) can be ofalmost zero, or from about +5 to about +30 micrometers to produceacceptable seam quality improvement result. In embodiments, thethickness differential may be in the range of from about +8 to about +20micrometers based from optimum ease of ultrasonic seam welding operationfor good seam bonding strength consideration.

A satisfactory overlap width (i.e., mated surface region or contiguouscontact width), measured in a direction perpendicular to the length ofthe mated surface region (i.e., measured in a direction transversely ofthe final belt), is between about 0.5 millimeters and about 1.8millimeters. In embodiments, the overlap length is between about 0.8millimeters and about 1.5 millimeters. Optimum overlap for best overallseam quality improvement is achieved with an overlap width of betweenabout 1.0 millimeters and about 1.3 millimeters. The overlap widthshould preferably be at least about 7 times greater than the thicknessof the belt.

The final welded belt has, in embodiments, a maximum differential inseam centerline thickness of less than about +25 percent of thethickness of the sheet prior to forming into a seamed belt to minimizethe adverse effects of collisions between the seam or components thereofand various subsystems of electrostatographic imaging systems. Inembodiments, the minimum differential in seam centerline thickness ismore than about +4.5 percent of the thickness of the sheet prior toforming any seam to avoid any pronounced depression which could collecttoner particles and other undesirable debris.

The surface profile of the new first angular or sloped surface and thenew second surface, respectively, of flexible imaging member 10 can bemodified (by including altering the shape thereof and reducing thethickness thereof) by any suitable well known technique. Typical surfacetreatment methods include chemical treatment and mechanical treatmentsuch as abrasion, grinding, slicing, laser ablation, or polishing.

For example, in addition to the mentioned tilted or slantedcross-sectional cutting techniques, the two opposite ends of marginalregions 12 and 14 having vertical or perpendicular cuts canalternatively be created, as demonstrated above, and then modified byadopting a super polishing process to displace or remove materialswithin the belt surfaces to produce a pair of angled, matching orreciprocal ends for mating and ultrasonic welding. This process willalso yield the seam design set forth in FIG. 4.

The angled or beveled ends may be created using a blade or knife andcutting through the imaging sheet at the desired angle. In embodiments,a blade or knife is a component of an apparatus that is suitable formaintaining the blade at the desired angle and allows for repeatablecuts, with respect to the surface angle, to be made. An example of asuitable apparatus is shown in FIGS. 7-11. A cutting assembly inaccordance with the embodiment in FIGS. 7-11 generally comprises asupport member and a blade support member attached to the supportmember. A cutting blade is attached to the blade support member suchthat the cutting blade is provided at an angle relative to the surfaceof the imaging sheet to provide the desired cross-sectional angled cut.The blade support member may be fixedly connected to the support memberor may be pivotably connected to the support member.

With reference to the embodiment in FIGS. 7-11, a cutting assembly 100includes a primary support member 120, a blade support member 140connected to the primary support member, and a blade mount assembly 170connected to the blade support member. Each of the primary supportmember and the blade support member includes a proximate end, a distalend, an upper surface, a lower surface, and opposing side surfaces. Asshown in the embodiment in FIGS. 7-11, primary support member 120includes a recessed portion 126 (along the right surface) extending fromthe proximate end 123 and from the bottom 125. Blade support member 140is positioned in recess 126 and is pivotably connected to primarysupport member 120 via pin 133 that is inserted through apertures 154 ofthe blade support member and corresponding aperture 134 of the primarysupport member. In other embodiments, support member 120 does notinclude a recess, and blade support member may be connected to one ofthe side surfaces.

A blade mount assembly 170, which comprises a cutting blade 174, isattached to blade support member 140. In embodiments, a blade assemblymay be fixedly attached to the blade support member. In the embodimentsin FIGS. 7-11, blade assembly 170 is releasably attached to bladesupport member 140. Blade assembly 170 includes blade mounting body 172having a cutout portion 173 disposed along the bottom edge of mountingbody 172, a blade or knife 174, and bracket 180. A portion of the blade174 is dimensioned to fit in cutout portion 173 of mounting body 172. Ablade locking fastener 181 is inserted through aperture 182. Bladelocking fastener 181 includes collar 183 that is dimensioned to fit inslit 178 of blade 174. Blade support member 140 includes a support arm142 and a lower portion 150 integral with support arm 142 and disposedtoward the proximate end of support member 140. Blade support member 140also includes a slot 152 dimensioned for receiving mounting body 172 ofblade mount assembly 170. As shown in FIGS. 7-11, support arm 142includes apertures 160 and 161. Aperture 160 is in alignment with andextends into slot 152. A fastener 189 may be inserted into aperture 160and subsequently into bore 188 of mounting body 172 to fasten blademounting assembly 170 to blade support member 140.

The desired angle position of blade 176 is achieved by the manner inwhich the blade assembly is connected to the blade support member (suchas blade support member 140). For example, with reference to theembodiment in FIGS. 7-11, support arm 142 is angled relative to supportmember 120 and slot 152 is perpendicular to support arm 142 such that,when blade mount assembly 170 is connected to blade support member 140,blade assembly 174 is oriented at an angle relative to the lower surface151, of blade support member 140, which is generally substantiallyparallel with the surface of an associated imaging sheet to be cut. Inalternative embodiments, support arm 142 of blade support member 140 maybe substantially parallel to support member 120 and/or the imaging sheetto be cut, but the blade assembly 170 is connected or mounted to thesupport arm or blade support member in a manner such that it ispositioned at an angle relative to the imaging sheet to be cut. Thecutting blade is therefore oriented at an angle relative to the surfaceof an imaging sheet to provide an angled or beveled cut along theimaging sheet.

The cutting blade is generally positioned at a fixed angle relative tothe surface to be cut. This is desirable to produce substantiallyidentical surface cuts at successive cutting locations along the imagingsheet member. The angle may be changed by moving the blade assembly upor down in slot 152. In embodiments, the angle may be changed by restingthe blade mount assembly 170 on a vacuum, which is used to hold theimaging sheet member in place during cutting. This causes the blade tobe slightly flexed and changes the angle of the blade.

The magnitude of the angled or beveled cut may be selected as desiredfor a particular purpose or intended use, but in accordance with thepresent disclosure is less than about 90°. In one embodiment, the angledor beveled cut is about 45° or less. In another embodiment, the angledor beveled cut is about 30° or less. In still another embodiment, theangled or beveled cut is about 15° or less. In a further embodiment, theangled or beveled cut is from about 5° to about 15°.

To ensure that the cutting blade maintains contact with the imagingsheet to be cut, the blade support member may be downwardly biasedtoward the surface of the imaging sheet. In embodiments, the bladesupport member, and hence the blade assembly, are downwardly biased by aforce sufficient to bias the blade support member and blade assemblydownward but maintain the blade support member and blade assembly in aselected position. With reference to the embodiment in FIGS. 7-11, thebiasing force is achieved with a spring 224 connected to pins 220 and222. Pin 222 is positioned in aperture 147 located in upper flange 146of blade support member 140. Pin 220 is substantially parallel with pin222 and is positioned in aperture 138 of flange 130 of support member120. Pin 220 extends through cutout 148, which is recessed relative tothe proximate end of blade support member 140. As shown in theembodiment in FIGS. 7-11 the spring 224 is hooked to pins 220 and 222around grooves 221 and 223, respectively. Other means, to downwardlybias the blade support member include, but are not limited to aircylinder, electrical solenoid, and the like.

In embodiments, the cutting assembly may include a means for retainingthe blade support arm in a downwardly biased position. With reference tothe embodiment in FIGS. 7-11, the means to retain blade support memberin a downwardly biased position is provided by screw 250. Screw 250 isreleasably inserted into aperture 132 of threaded bore 252. Threadedbore 252 is exposed along the vertical surface of recess 126. Screw 250may be moved into bore 252 such that screw 252 contacts the uppersurface of portion 144 of blade support member 140 and prevents bladesupport member 140 from being pivoted upwardly. This may be useful toprevent the blade support member and the blade from being pivoted upwardduring a cutting operation, which may result in a discontinuous ornon-uniform cut. The means for retaining the blade support member in adownwardly biased position may also include, but is not limited to,retainer clips, a wedge, a pin, and the like.

In embodiments, cutting blade 174 is a single edge or chiseled edgeconfiguration. With reference to FIG. 12, the cutting blade 174 is achiseled edge blade having a generally flat or planar bottom 177 and anangled blade edge 176. The angle B of the blade is, in embodiments about45° or less relative to the bottom flat surface 177 of the blade. Inother embodiments, the chiseled edge blade has an angle of about 30° orless. In still other embodiments, the chiseled edge has an angle ofabout 15° or less. A double edge blade may be used, but is lessdesirable because the material being cut tends to ride up on the bladeof a blade with a double edge configuration.

In embodiments, a cutting assembly may include a guide member such asguide member 230 positioned adjacent forward of the cutting blade alongthe direction in which the imaging sheet will be cut. With reference tothe embodiment in FIGS. 7-11, cutting assembly 100 includes a guidemember 230 positioned in slot 156 of blade support member 140. Guidemember 230 is held in position by a pin inserted through apertures 158of blade support member 140 and apertures 239 of guide member 230. Asshown in the embodiment in FIGS. 8-13 slot 156 is a U-channel and theguide member 230 includes a flange 234 extending under one of the legsof the U-channel and positioned substantially adjacent to cutting blade176. The guide member is formed from a relative soft polymeric materialand is adapted to engage and ride along the surface of the imaging sheetto be cut prior to the knife. In this respect, the guide member isadapted to hold down the material or imaging sheet to be cut and keepthe sheet from riding up and down the blade as the sheet is cut. Inembodiments, at least a portion of the bottom surface of the guidemember is generally planar and adapted to ride generally parallel to thesurface of the imaging sheet to be cut. In the embodiment in FIGS. 7-11,the guide member 230 includes a portion 236 that is generally planar andcapable of riding parallel to a surface of an imaging sheet to be cut.The guide member 230 also includes a lead edge 238 that is formed by aportion of the bottom surface of the guide member and angled upwardlyaway from portion 236. Without being bound to any particular theory, theuse of a lead edge such as lead edge 238 reduces the shear force appliedto the imaging sheet as the guide member comes in contact with thesheet. The guide member may be fixed in position or may be pivotableabout the pin 240 such that the guide member may pivot to accommodatefor contour changes or undulations along the surface of an imaging sheetto be cut.

To cut an imaging sheet to provide an angled or beveled cut, an imagingsheet is provided and held in a fixed position. With reference to FIG.13, an apparatus or system for providing angled surfaces on an imagingsheet with a cutting assembly in accordance with the present disclosureis shown. An imaging member sheet 300 may be supported or held in placeon a support member, such as table or platen 310 and may be held inplace by vacuum (not shown). A cutting tool 100, such as the cuttingassembly 100 described with reference to FIGS. 7-11 is provided andpositioned along a first or home edge of the apparatus. As shown in FIG.14, the right side of the Figure represents the cutting assembly in ahome or starting position and the left side represents the cuttingassembly in an end position after a cut has been made. The blade supportarm is positioned such that the guide member is in full contact with thefirst major exterior surface 302 of the imaging sheet and the cuttingblade is cutting blade with the lower cutting surface. As shown in FIG.13, roller 208 engages a surface of ramp portion 308. The cuttingassembly is moved along the surface 308 and down the ramp 309 toward thefirst major exterior surface 302 of imaging member sheet 300. Thecutting tool is then moved along the surface of the imaging sheet suchthat the cutting blade passes through the cross-sectional thickness ofthe imaging sheet to provide an angled or beveled cut. In embodiments,the cutting assembly is moved in a direction perpendicular to the majorexterior surfaces 302, 304 of the imaging sheet. In other embodiments,the cutting tool may be moved at an angle greater than or less than 90°relative to the edges of the major exterior surfaces 302 and 304. Theimaging tool is moved across the imaging sheet cutting through thethickness of the sheet to a second major exterior surface 304 or endposition. After the cutting operation, and in no particular order, thecutting tool is moved back to the home position and the imaging sheet ispulled or moved to a desired length. The process is repeated again toprovide a sheet with ends having matching angled or beveled cuts. Thesheet is then looped and the angled or beveled cuts on the ends of thesheet to form a butt-lap seam.

In embodiments, a method is provided for positioning the cutting blade176 above, i.e., off of, the surface of the imaging sheet prior toreturning the cutting assembly to the home position. In the embodimentin FIGS. 13 and 14, a ramp 320 is provided at a position adjacent thesecond side major exterior surface 304 of the imaging sheet such thatafter the cutting blade passes through the second major exterior surface304 of the imaging sheet, the cutting assembly continues to move in thecutting direction until a roller 208 attached to the blade supportmember 140 engages the ramp 320. As the roller moves up the ramp, aforce is applied to the blade support member 140 sufficient to overcomethe downward biasing force of spring 224, and the blade support member140 is pivoted upward toward the top of support member 120. As shown inFIGS. 7-11, blade support member 140 includes a portion 144 integralwith vertical flange 146 and support arm 142. A housing 260 is connectedto support member 120 and comprises a retainer plunger pin for retainingthe blade support member 140 in an upward position. Housing 260 ispositioned within aperture 136 of support member 120. Housing 260 is ahollow cylindrical configuration with an aperture 260 dimensioned toreceive plunger pin 268. A spring 264 is disposed within the hollowportion of housing 260 and is in engaging contact with plunger pin 268.An adjusting screw 266 is inserted into an end of the housing andapplies a force on spring 264 sufficient to bias plunger pin 268 throughaperture 261 of housing 260. As the roller engages and passes along theramp 300, blade support member 140 is upwardly biased and aperture 145on portion 144 is moved into alignment with aperture 136 of supportmember and aperture 261 of housing member 260. When aperture 145 alignswith aperture 261, the biasing force applied on plunger pin 268 byspring 264 causes plunger pin 268 to be released and extend throughaperture 145. Plunger pin 268 then catches a portion of aperture 145. Asthe cutting assembly is moved back toward a home or starting position,the upward biasing force applied by roller 208 engaging the ramp isreleased and blade support member 140, and therefore blade 174, ismaintained in an upward position above or off of the imaging sheet. Whenthe cutting assembly is returned to the home position, a tool or devicemay be used to apply a force on and depress plunger pin 268 such thatblade support member 140 is released and downwardly biased, such as byspring 224, to engage the imaging sheet to be cut. For example, in FIG.13, when the cutting assembly 100 returns to the home position, a member412 may be provided to engage and depress plunger pin 208 and releaseblade support member 140, which is downwardly biased such that theassembly is ready to begin a new cutting process.

The use of a cutting assembly, such as that described with reference toFIGS. 7-13, provides repeatable cuts at the same angle on successivemarginal edges. It is desirable to produce successive cuts havingsubstantially the same angled surface for mating the angled surfacesbecause the cuts that are being mated are not “sister” cuts. Providing atool and method such as that of FIGS. 7-13 that produces repeatable cutsprovides for better mating of the cuts and reduces the amount of weldsplash associated with forming the seam when the marginal ends arewelded together.

The seam designs disclosed herein are capable of providing imagingmember belts with significant seam quality improvement to substantiallyenhance imaging member belt production yield and effectively reduce thebelt unit manufacturing cost. Implementation of this seamed beltpreparation not only eliminates the need of labor intensive and timeconsuming manual seam inspection procedures it also increases theproduction belt yields that are otherwise lost as rejects due to thepresence of seam protrusion spots. Thus, the seaming of flexible imagingmember belts according to this disclosure delivers a seam configuration,having significant improved qualities and better physical/mechanicalattributes including smoother surface profile, little or no seamsplashing, absence of protrusion spots, thinner cross-sectionalthicknesses, and little or no physical discontinuity to enhance cleaningblade performance and suppress the premature onset of fatigue inducedseam cracking/delamination frequently produced during extendedelectrophotographic imaging and cleaning processes.

A number of examples are set forth hereinbelow and are illustrative ofdifferent compositions and conditions that can be utilized in practicingthe seam designs disclosed herein. All proportions are by weight unlessotherwise indicated. It will be apparent, however, that the developmentcan be practiced with many types of compositions and can have manydifferent uses in accordance with the disclosure above and as pointedout hereinafter.

Example I

An electrophotographic imaging member web was prepared by providing aroll of titanium coated biaxially oriented thermoplastic polyester (PET,Melinex, available from ICI Americas Inc.) substrate having a thicknessof 3 mils (76.2 micrometers). Applied thereto, using a gravureapplicator, was a solution containing 50 parts by weight of3-aminopropyltriethoxysilane, 50.2 parts by weight of distilled water,15 parts by weight of acetic acid, 684.8 parts by weight of 200 proofdenatured alcohol, and 200 parts by weight of heptane. This layer wasthen dried to a maximum temperature of 290° F. (143.3° C.) in a forcedair oven. The resulting blocking layer had a dry thickness of 0.05micrometer.

An adhesive interface layer was then prepared by applying to theblocking layer a wet coating containing 5 percent by weight, based onthe total weight of the solution, of polyester adhesive (Mor-Ester49,000, available from Morton International, Inc.) in a 70:30 volumeratio mixture of tetrahydrofuran/cyclohexanone. The adhesive interfacelayer was dried to a maximum temperature of 275° F. (135° C.) in aforced air oven. The resulting adhesive interface layer had a drythickness of 0.07 micrometers.

The adhesive interface layer was thereafter coated with aphotogenerating layer containing 7.5 percent by volume of trigonalselenium, 25 percent by volume ofN,N′-dipheny-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, and67.5 percent by volume of polyvinylcarbazole. This photogenerating layerwas prepared by introducing 160 gms of polyvinylcarbazole and 2,800 misof a 1:1 volume ratio of a mixture of tetrahydrofuran and toluene into a400 oz. amber bottle. To this solution was added 160 gms of trigonalselenium and 20,000 gms of ⅛ inch (3.2 millimeters) diameter stainlesssteel shot. This mixture was then placed on a ball mill for 72 to 96hours. Subsequently, 500 gms of the resulting slurry were added to asolution of 36 gms of polyvinylcarbazole and 20 gms ofN,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diaminedissolved in 750 mls of 1:1 volume ratio of tetrahydrofuran/toluene.This slurry was then placed on a shaker for 10 minutes. The resultingslurry was thereafter applied to the adhesive interface by extrusioncoating to form a layer having a wet thickness of 0.5 mil (12.7micrometers). However, a strip about 3 mm wide along one edge of thecoating web, having the blocking layer and adhesive layer, wasdeliberately left uncoated by any of the photogenerating layer materialto facilitate adequate electrical contact with the ground strip layerthat is applied later. This photogenerating layer was dried to a maximumtemperature of 280° F. (138° C.) in a forced air oven to form a drythickness photogenerating layer having a thickness of 2.0 micrometers.

This coated imaging member web was simultaneously coated over with acharge transport layer and a ground strip layer by co-extrusion of thecoating materials. The charge transport layer was prepared byintroducing into an amber glass bottle in a weight ratio of 1:1 (or 50%wt of each) ofN,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine andMakrolon 5705, a Bisphenol A polycarbonate thermoplastic having amolecular weight of about 120,000 commercially available fromFarbensabricken Bayer A. G. The resulting mixture was dissolved to give15 percent by weight solid in methylene chloride. This solution wasapplied on the photogenerator layer by extrusion to form a coating whichupon drying gave a thickness of 24 micrometers.

The strip, about 3 mm wide, of the adhesive layer left uncoated by thephotogenerator layer, was coated with a ground strip layer during theco-extrusion process. The ground strip layer coating mixture wasprepared by combining 23.81 gms of polycarbonate resin (Makrolon 5705,7.87 percent by total weight solids, available from Bayer A. G.), and332 gms of methylene chloride in a carboy container. The container wascovered tightly and placed on a roll mill for about 24 hours until thepolycarbonate was dissolved in the methylene chloride. The resultingsolution was mixed for 15-30 minutes with about 93.89 gms of graphitedispersion (12.3 percent by weight solids) of 9.41 parts by weight ofgraphite, 2.87 parts by weight of ethyl cellulose and 87.7 parts byweight of solvent (Acheson Graphite dispersion RW22790, available fromAcheson Colloids Company) with the aid of a high shear blade dispersedin a water cooled, jacketed container to prevent the dispersion fromoverheating and losing solvent. The resulting dispersion was thenfiltered and the viscosity was adjusted with the aid of methylenechloride. This ground strip layer coating mixture was then applied, byco-extrusion with the charge transport layer, to the electrophotographicimaging member web to form an electrically conductive ground strip layerhaving a dried thickness of about 14 micrometers.

The resulting imaging member web containing all of the above layers wasthen passed through a maximum temperature zone of 257° F. (125° C.) in aforced air oven to simultaneously dry both the charge transport layerand the ground strip.

An anti-curl coating was prepared by combining 88.2 gms of polycarbonateresin (Makrolon 5705, available from Goodyear Tire and Rubber Company)and 900.7 gms of methylene chloride in a carboy container to form acoating solution containing 8.9 percent solids. The container wascovered tightly and placed on a roll mill for about 24 hours until thepolycarbonate and polyester were dissolved in the methylene chloride.4.5 gms of silane treated microcrystalline silica was dispersed in theresulting solution with a high shear dispersion to form the anti-curlcoating solution. The anti-curl coating solution was then applied to therear surface (side opposite the photogenerator layer and chargetransport layer) of the electrophotographic imaging member web byextrusion coating and dried to a maximum temperature of 220° F. (104°C.) in a forced air oven to produce a dried coating layer having athickness of 13.5 micrometers.

Example II

An imaging belt with beveled end edges is then formed employing thecutting assembly of FIGS. 7-11 and a cutting apparatus as described inFIGS. 13 and 14. Imaging material in roll form is unwound and threadedinto a miter cutting apparatus described with respect to FIG. 13. Thelead edge of the material overhangs a lower cutting edge at initialthread up. The miter cutter assembly 100 then traverses across thematerial cutting off the overhung portion of imaging material. The exactposition of the lead edge of the next image sheet is now known. The leadedge is then picked up by vacuum and pulled out to the desired sheetlength. Vacuum plentums under the material 300 are then turned on via asolinoid operated vacuum valve, thus sucking the material securely down.The miter cutter 100 then begins its travel across the width of thematerial via a rodless air cylinder, or any other suitable means. As itproceeds, roller 208 rides down on ramp 308 and comes down to the sameelevation as the upper surface of the vacuum and lower shear plentum.Roller 208 then engages, and rides up the edge of the material 302. Asit does so, shoe 232 also rides up onto the material, holding theimaging material down against the shear vacuum plentum. The miter knife176 then enters into the edge of the material thereby slicing thematerial at the angle of the knife. The shoe 232 must be as close aspossible to the shear knife so as to keep the imaging material downagainst the lower shear edge. The imaging material has a tendency toride up the cutting knife, which causes a scalloped or non-paralleledge.

As the knife assembly completes its cut across the width of the materialand exits the opposite edge 304, the roller 208 then hits the lead edgeof ramp 320 and begins its ride up the ramp, thereby rotating supportmember 140 about hinge pin 154. At the top of the ramp, (shot) pin 268is forced into an elongated slot 145 in position 144 of support member140. Slot 145 captures the rotating portion of the miter cut assembly inthe upward position. The traversing rodless air cylinder then hits itsend of travel, and a proximity switch tells the logic controller toactivate an air valve to send the miter cutting assembly back home. Asthe assembly approaches home, pin 412 enters through the elongated slotin 146, and then hits pin 268, thereby disengaging pin 268, and allowingthe assembly and particularly support member 140 to rotate downwardslightly until roller 208 hits ramp 308. The home proximity switch isthen made, and the miter cutting sequence is now complete.

Example III Physical and Mechanical Evaluation

A seam design (control) such as that set forth in FIG. 1 was compared tothree respective disclosure seams prepared according to the processesdescribed above. These seams were analyzed for surface topology using asurface analyzer, Surftest 402, available from Mitutoyo Company. Thesurface profile obtained for the control seam design set forth in FIG. 5had a 1.0 micrometer seam splash, a splash height of 68 micrometer, anda rough surface roughness Ra value of 7.1.

In sharp contrast, the three low profile seam designs of this disclosurehad a smoother seam region topology, a small 0.16 micrometer splash, asubstantially reduced splash height of about 19 micrometers, and asurface roughness Ra value of 1. See FIG. 6.

In addition, seam thickness measurements, using a micrometerdemonstrated that the seams of the present disclosure exhibited asignificant reduction in seam region thickness. These seams exhibitedthicknesses of only about 8.1 to about 8.7 percent greater than the bulkof the imaging member. By comparison, the seam counterpart of thecontrol seam design exhibited a thickness of about 60 percent greaterthan the bulk imaging member.

The control seam and the three seam design of this disclosure werefurther evaluated for tensile seam rupture strength using an InstronMechanical Tester. The seams of the disclosure produced a seam strengthof about 8.9 and about 9.5 kgs/cm slightly lower than the 10.1 kgs/cmrupture strength obtained for their control seam counterpart.Nonetheless, these values still significantly exceeded the imagingmember belt seam strength specification of 6.3 kgs/cm to assuremechanical seam integrity during dynamic imaging member belt machinefunction in the field.

Example IV Dynamic Imaging Belt Cycling

The prepared electrophotographic imaging member web of Example I wasagain used to prepare a control seamed imaging member belt having awidth of 353 mm a circumference of precisely 559.5 mm. Seamed beltshaving the same dimensions as the control seamed belt, but comprising a150 slanting angle butt-lap joint according to the abrading polishtechnique and belt fabrication procedures described above, were alsoproduced. Both the control and the electrophotographic imaging memberseamed belts of this disclosure were each dynamically cycled tested, tothe point of onset of seam failure, in a xerographic machine utilizing abelt support module comprising a 25.24 mm diameter drive roller, a 25.24mm diameter stripper roller, and a 29.48 mm diameter tension roller toexert to each belt a tension of 1.1 pounds per inch. The belt cyclingspeed was set at 65 prints per minute.

The control imaging member belt, was cyclic tested to produce anequivalent of only about 56,000 print copies and terminated for thereason of notable onset of seam cracking/delamination.

The very same machine belt cycling procedures were repeated for thebutt-lap seamed belt of this disclosure. Neither seam failure norcleaning blade wear problem were observed after completion ofapproximately 500,000 equivalent print copies of belt cyclic testing.

Consequently, the thin profile, butt-lap seam design disclosed hereinreduces seam cracking/delamination problems, provides a simple seamedbelt fabrication method utilizing a conventional ultrasonic seam weldingprocess that minimizes seam splash junction physical discontinuity,provides smoother surface topology of little or no seam splashing,effects seam region thickness reduction, produces a dimensionally stableimaging member belt, suppresses cleaning blade wear, and veryimportantly, produces a prepared seam substantially free of highprotrusion spots to thereby reduce seamed imaging member belt rejectionrates and increase imaging member belt production yield as well.Furthermore, the seam quality is improved utilizing the seam design ofthis disclosure such that the manual seam inspection steps may, in someinstances, be eliminated.

While particular embodiments have been described, alternatives,modifications, variations, improvements, and substantial equivalentsthat are or may be presently unforeseen may arise to applicants orothers skilled in the art. Accordingly, the appended claims as filed andas they may be amended are intended to embrace all such alternatives,modifications variations, improvements, and substantial equivalents.

1. A process for producing a seamed, flexible electrostatographicimaging member belt comprising: a) providing a flexible, substantiallyrectangular, electrostatographic imaging sheet having a first majorexterior surface opposite and parallel to a second major exteriorsurface and a first marginal end region of said sheet opposite andparallel with a second marginal end region; b) providing an apparatusfor cutting the imaging sheet, the apparatus comprising i) a supportmember, ii) a blade support member connected to the support member, andiii) a blade assembly connected to the blade support member, the bladeassembly having a cutting blade, wherein the blade support membercomprises an upper surface and a lower surface, the lower surfacedefines a plane and the cutting blade defines a plane, and wherein theplane of the lower surface and the plane of the cutting blade jointogether along a line and wherein the angle between the planes is lessthan 90°; c) shaping said first marginal end region at an angle with theapparatus to form a first new sloping surface between the first majorexterior surface and the second major exterior surface; d) shaping saidsecond marginal end region at an angle with the apparatus to form asecond new sloping surface between the first major exterior surface andthe second major exterior surface, wherein the second new slopingsurface is substantially parallel with the first new sloping surface; e)forming the sheet into a loop and overlapping said first new slopingsurface with said second new sloping surface to form a mated region; andf) joining said first new sloping surface to said second new slopingsurface in the mated region to form a seam.
 2. The process according toclaim 1, wherein the blade support member is pivotably connected to thesupport member.
 3. The process according to claim 2, wherein the bladesupport member is downwardly biased toward an upper surface of theimaging sheet.
 4. The process according to claim 3, further comprisingapplying a force to bias the blade support member upward and above theupper surface of the imaging sheet after the cutting blade is movedthrough the second major exterior surface of the imaging sheet.
 5. Theprocess according to claim 4, wherein the apparatus further comprises ameans to retain the blade support member and cutting blade in an upwardposition above the upper surface of the imaging sheet.
 6. The processaccording to claim 5, further comprising returning the apparatus to aposition adjacent the first major exterior surface of the cutting sheet;positioning the image sheet to provide a new location to be cut;releasing the retainer means on the apparatus such that the bladesupport arm and cutting blade are downwardly biased adjacent the surfaceof the imaging sheet; performing another cutting operation to provide asecond sloping surface across the imaging sheet.
 7. The process of claim1, wherein the apparatus further comprises a first pin connected to apivot arm on the blade support member, a second pin connected to thesupport member and generally parallel to the first pin, and a meansattached to the first and second pins for biasing the pivot arm downwardtoward a surface of an associated imaging sheet to be cut.
 8. A processfor producing a seamed, flexible electrostatographic imaging member beltcomprising: a) providing a flexible, substantially rectangular,electrostatographic imaging sheet having a first major exterior surfaceopposite and parallel to a second major exterior surface and a firstmarginal end region of said sheet opposite and parallel with a secondmarginal end region; b) providing an apparatus for cutting the imagingsheet, the apparatus comprising (i) a support body, and (ii) a bladesupport member pivotably connected to the support body and biased awayfrom the support body, the blade support member comprising a lowersurface, a guide member positioned in a slot in the lower surface, and acutting blade; wherein the cutting blade comprises a flat surface and anangled straight blade edge, the blade edge facing towards the guidemember; wherein the lower surface defines a plane and the flat surfaceof the cutting blade defines a plane, the plane of the lower surface andthe plane of the flat surface of the cutting blade join together along aline, and the angle between the two planes is less than 90°; and whereinthe guide member includes a generally planar lower surface extendingbelow the slot and adapted to ride generally parallel to a surface ofthe associated substrate; c) shaping said first marginal end region atan angle to form a first new sloping surface between the first majorexterior surface and the second major exterior surface; d) shaping saidsecond marginal end region at an angle to form a second new slopingsurface between the first major exterior surface and the second majorexterior surface, wherein the second new sloping surface issubstantially parallel with the first new sloping surface; e) formingthe sheet into a loop and overlapping said first new sloping surfacewith said second new sloping surface to form a mated region; and f)joining said first new sloping surface to said second new slopingsurface in the mated region to form the belt, wherein the first andsecond new sloping surfaces form a continuous seam from a first side ofthe belt to a second side of the belt, wherein the first and secondsloping surfaces have an angle substantially equal to each other, theangle of the first and second sloping surfaces being less than 90°. 9.The process according to claim 8, wherein the angle between the twoplanes is about 45° or less.
 10. The process according to claim 8,wherein the angle between the two planes is about 30° or less.
 11. Theprocess according to claim 8, wherein the angle between the two planesis from about 5° to about 15°.
 12. A method for producing a seamed,flexible electrostatographic imaging member belt comprising: providing aflexible, substantially rectangular, electrostatographic imaging sheethaving a top surface, a bottom surface, a first major exterior surfaceopposite and parallel to a second major exterior surface and a firstmarginal end region of said sheet opposite and parallel with a secondmarginal end region; providing a cutting apparatus comprising i) asupport member having an upper surface, a lower surface, a firstvertical surface, a second vertical surface, a proximate end, and adistal end, ii) a blade support member pivotably connected to thesupport member, the blade support member comprising a pivot arm having aproximate end, a distal end, an upper portion adjacent the proximal end,and a lower portion adjacent the proximate end of the blade supportmember; and iii) a blade mount assembly connected to the blade supportmember, the blade mount assembly comprising a cutting blade having ablade edge wherein the cutting blade is oriented at an angle of about45° or less relative to the top and bottom surfaces of the imagingsheet, wherein the blade support member comprises an upper surface and alower surface, the lower surface defines a plane and the cutting bladedefines a plane, and wherein the plane of the lower surface and theplane of the cutting blade join together along a line and wherein theangle between the planes is less than 90°; shaping said first marginalend region at an angle with the apparatus to form a first new angledsurface between the first major exterior surface and the second majorexterior surface; shaping said second marginal end region at an anglewith the apparatus to form a second new angled surface between the firstmajor exterior surface and the second major exterior surface, whereinthe second new angled surface is substantially parallel with the firstnew angled surface; forming the sheet into a loop and overlapping saidfirst new angled surface with said second new angled surface to form amated region; and joining said first new angled surface to said secondnew angled surface in the mated region to form a seam.
 13. The methodaccording to claim 12, wherein each of the first and second angledsurfaces has an angle of about 15° or less.
 14. The method according toclaim 12, wherein each of the first and second angled surfaces has anangle of from about 5° to about 15°.
 15. The method according to claim12, wherein the cutting apparatus further includes a guide membercomprising a i) proximate end adjacent the blade edge of the cuttingblade, ii) a distal end, and iii) a lower surface, a portion of thelower surface adjacent the proximate end of the guide member having agenerally planar surface defining a first plane generally parallel tothe upper surface of the imaging sheet, and a portion of the lowersurface adjacent the distal end of the guide member being angled upwardout of the first plane of the lower surface of the guide member.
 16. Themethod according to claim 12, wherein the cutting apparatus furthercomprises a first pin connected to the pivot arm, a second pin connectedto the support member and generally parallel to the first pin, and ameans attached to the first and second pins for biasing the pivot armdownward toward a surface of an associated imaging sheet to be cut. 17.The method according to claim 16, wherein the means for biasing thepivot arm downward is a spring.
 18. The method according to claim 12,further comprising applying a force to bias the blade support memberupward and above the upper surface of the imaging sheet after thecutting blade is moved through the second major exterior surface of theimaging sheet; retaining the blade support member and cutting blade inan upward position above the upper surface of the imaging sheet using aretainer means; returning the apparatus to a position adjacent the firstmajor exterior surface of the cutting sheet; positioning the image sheetto provide a new location to be cut; releasing the retainer means on theapparatus such that the blade support arm and cutting blade aredownwardly biased adjacent the surface of the imaging sheet; andperforming another cutting operation to provide the second angledsurface.